Investigation of electrochemical post-processing procedure for Ti-6Al-4V lattice structure manufactured by direct metal laser sintering (DMLS)

Abstract

Additive manufacturing has become very popular nowadays to create complex geometries that cannot be achieved by any other manufacturing processes. The purpose of this study is to investigate and characterize the electrochemical polishing and chemical etching methods as a post-process treatment to improve the surface finish of lattice structures made from Ti-6Al-4V manufactured by direct metal laser sintering (DMLS). A lattice sample is designed with external and internal struts to compare the influence of the post-processing on different features. The post-processing parameters are studied via the Taguchi method. This work will provide critical information on the surface and geometrical characterization as well as the post-process treatment of a Ti-6Al-4V lattice. The metrological data will be analyzed to determine how the post-process treatment affects the surface finish, considering the final roughness and geometrical integrity of lattice samples. It is found that the material removal rate was more important at the edges, specifically on the external features. It was also confirmed that the average roughness is linked to the material removal for both processes. The more material is removed from the parts, the better the surface finish. It is also found that the etching process helps the electrochemical polishing go deeper inside the geometry.